The Kyoto Protocol has been adapted by 163 countries around the world as a cornerstone of the fight against global warming. Those nations that have ratified the protocol commit to reducing their emissions of carbon dioxide and five other so-called greenhouse gases. A growing number of scientists claim emissions of those gases are beginning to affect the global climate. To date, the United States has not bought in. One of the world's leading consumers of the fossil fuels that produce carbon dioxide, the U.S. can't even decide whether to regulate emissions of CO2. Now, that decision will be made by the highest court in the land.
The U.S. Supreme Court this week agreed to consider whether the Bush administration must regulate carbon dioxide, or CO2, as a pollutant.
The most prevalent of the so-called "greenhouse gasses,' CO2 is released when fossil fuels like coal or gasoline are burned. Once in the atmosphere, it traps the earth's heat -- much like a greenhouse. And many scientists claim greenhouse gasses are the leading cause of global warming.
During his first bid for the Oval Office, President Bush favored government regulation of CO2 emissions. But after the dust settled from the 2000 elections, Bush reversed himself -- saying regulation would be too expensive for businesses and voluntary efforts were the best method of curtailing CO2 emissions.
But a coalition of states, cities and environmental groups argue that the Environmental Protection Agency, or EPA, is required to regulate CO2 emissions under the Clean Air Act because CO2 is a pollutant.
The Bush administration maintains that carbon dioxide -- unlike other chemicals that must be controlled to assure healthy air -- is not a pollutant under the Clean Air Act and even if it were, the EPA has discretion over whether to regulate it.
Last year, a federal appeals court sided with the administration, leaving the coalition no other option but to appeal to the Supreme Court.
This week's announcement that the High Court will hear the case sets the stage for what could be one of the most important environmental decisions in history. A ruling is expected next year.